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How can I modify a wired air conditioning control to be wireless or IR remote control? Answered

The main intention is just to "turn on" and "turn off" the air conditioner wireless-ly.


X-10 is the fancy way. It's a DIY "home control system" which includes modules for remotes.

A much less expensive way is just to buy a $20 plug in module. Radio Shack used to sell them, but I got my most recent one through Amazon.


If your air conditioner is running off 208V 3-phase, you may need do to your own Google search. Remember, Google Is Your Friend.

Seen that already, and I knew Mr. G for very long time already my friend.
I prefer "hacking" it rather than buy stuff like that which will turn off the main power and reset the settings.

As far as I found from Mr. G, they're just too complicated and use chip controller as well. And if I live in US, I can find and order the component easily.

Anyway, I might post a picture or diagram of the wired air conditioner control.

P.S. You might use this link next time for newbies like me. http://lmgtfy.com/
Using the phrase "Google is your friend" is already "out of fashion".

Mr. G is nice, but he is (as you surely know) somewhat obtuse :-)

The X-10 stuff is, as you say, too complex for the problem you're trying to solve. That was why I suggested the simple plug-in box with keyfob remote. We have two of them at home, one for the baby's room light, and one for a light in the bedroom we can turn off without getting up.

You can probably hack up your existing AC and remote to use an IR LED and photodetector, but it's not obvious to me that the total cost will end up being less than buying a self-contained unit. The overseas companies that make these things have economies of scale that are somewhat hard to beat, unless you already have the components in your parts bin. That argument ignores the pleasure of DIY work, obviously :-)

P.S. I could have been an a----e and referenced JFGI :-) Also, I remember when Yahoo was king of the search engines, and I was in grad school before there WAS a World Wide Web (thanks be to Tim).

At the moment, what I did was just add 2 wires and soldered to the pushbutton switch (power button). So whenever these 2 wires short circuited, then the air conditioner is turn on/off. What I know is that IR sends signal patterns at different frequency. But how to make it to do the same job as the pushbutton switch?

With commercial IR remotes, you need to have a receiver with a "decoder" that matches the transmitter. You can buy kits which are all set up for you, but that's still more complex than what you seem to be looking for. Just buy an IR diode and wire up a little battery-powered circuit yourself, and put it in a box (rip the guts out of a surplus TV remote, for example). On the air conditioner, connect a photodetector-based circuit with a relay to those two wires of yours, to close or open whenever the detector receives a signal.

Thanks for your hint, and after doing more research and I found this.

I got it working, but now the problem is I need to press it twice to turn on or off. Because the relay wouldn't switch back automatically to (NC), I guess if I don't switch it back, then it will drain the battery power. I just need to short circuit the power button, so not a continuous connection.

Do you have any suggestion on how to make it automatically switch back to NC after 0.5 or 1 sec or even quicker?

It sounds like the power button on your AC unit is a normally-open momentary contact. Is that correct? If so, then you need to modify the receiver side so that _it_ acts like an NO momentary-contact, rather than a relay driven switch. In fact, isn't that just the thing? Maybe get rid of the relay entirely and just use the leads that are current set to power the relay go to your switch. You'll probably still need the protection diode to prevent back-current.

Yeah, it's normally-open momentary contact. And I already tried to remove the relay, but it doesn't work. I tested the contact points with a light bulb. And when I just connect the light bulb (powered with battery) to the points where the relay coils are, the bulb just light up. I also tried to break the positive side of D2 to V+, and connect the light bulb leads in between, also didn't work (this time the bulb doesn't light up, but the LED turn on when I pressed the remote control, and need to press again to turn off. Does Q3 is part of the relay? Can you give me some hints if you know the solution? My brain is about to explode now.